NETWORK DISCOVERY IN WIRELESS COMMUNICATION SYSTEMS

• US 20110141965A1
• Filed: 12/10/2009
• Published: 06/16/2011
• Est. Priority Date: 12/10/2009
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Tirronen, Mikko, Virtanen, Sami, Rantala, Enrico, Leppänen, Kari, Turunen, Markku, KASSLIN, Mika
• Granted Patent: US 8,842,605 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04W 36/0088 Scheduling hand-off measurements
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information

Abstract

Apparatuses may stay synchronized with a network via a beacon signal transmitted at a set interval. Communication-related activities may be planned around instances when beacon signals are expected, which may also be known as a target beacon transmission time (TBTT). Scanning opportunities, which are periods of time during which apparatuses may perform passive scanning, may be planned based on an interfere multiple of a network beacon signal interval. Apparatuses may, upon realizing a scanning opportunity, opt either to utilize the scanning opportunity or to participate in network beaconing. In example scenarios where apparatuses opt to utilize scanning opportunities, apparatuses may prepare a network information message and then enter a passive scanning mode. Apparatuses may remain in the passive scanning mode for the duration of the scanning opportunity, reacting when messages are received from devices outside of the network by transmitting the network information message.

Claims

1. A method, comprising:

identifying a scanning opportunity for an apparatus, the scanning opportunity being based upon an integer multiple of a network beacon signal interval;

if a determination is made in the apparatus to utilize the scanning opportunity, preparing a network information message and entering a passive scanning mode for the duration of the scanning opportunity; and

if a beacon message corresponding to another network is received in the apparatus while in the passive scanning mode, initiating transmission of the network information message.

2. The method of claim 1, wherein a start time and duration for the scanning opportunity are defined as integer multiples of the network beacon signal interval.

3. The method of claim 1, wherein if a determination is made to not utilize the scanning opportunity the apparatus is permitted to participate in beaconing within the network.

4. The method of claim 3, wherein when the apparatus participates in beaconing within the network during duration of the scanning opportunity, the apparatus does not initiate transmission of data frames during duration of the scanning opportunity.

5. The method of claim 1, wherein the network information message is modified by the apparatus prior to transmission to contain a network identifier corresponding to the other network, the network identifier being derived in the apparatus from the received beacon.

6. The method of claim 1, wherein the network information message contains information usable by other apparatuses when synchronizing to the beacon period of the network.

7. The method of claim 5, wherein the information usable by other apparatuses for synchronizing to the network further comprises diluted beacon period information.

8. The method of claim 1, wherein initiating transmission comprises participating in contention for access to a wireless communication medium.

9. The method of claim 1, wherein when entering the passive scanning mode the apparatus does not participate in beaconing for the duration of the scanning opportunity.

10. A computer program product comprising computer executable program code recorded on a computer readable storage medium, the computer executable program code comprising:

code configured to cause an apparatus to identify a scanning opportunity, the scanning opportunity being based upon an integer multiple of a network beacon signal interval;

code configured to, if a determination is made in the apparatus to utilize the scanning opportunity, cause the apparatus to prepare a network information message and enter a passive scanning mode for the duration of the scanning opportunity; and

code configured to, if a beacon message corresponding to another network is received in the apparatus while in the passive scanning mode, cause the apparatus to transmit the network information message.

11. The computer program product of claim 10, wherein a start time and duration for the scanning opportunity are defined as integer multiples of the network beacon signal interval.

12. The computer program product of claim 10, further comprising code configured to, if a determination is made to not utilize the scanning opportunity, cause the apparatus to participate in beaconing within the network.

13. The computer program product of claim 12, further comprising code configured to, if the apparatus participates in beaconing within the network during duration of the scanning opportunity, cause the apparatus to not initiate transmission of data frames during duration of the scanning opportunity.

14. The computer program product of claim 10, further comprising code configured to cause the apparatus to modify the network information prior to transmission to contain a network identifier corresponding to the other network, the network identifier being derived in the apparatus from the received beacon.

15. The computer program product of claim 10, wherein the network information message contains information usable by other apparatuses when synchronizing to the beacon period of the network.

16. The computer program product of claim 15, wherein the information usable by other apparatuses for synchronizing to the network further comprises diluted beacon period information.

17. The computer program product of claim 10, wherein initiating transmission comprises participating in contention for access to a wireless communication medium.

18. The computer program product of claim 10, further comprising code configured to cause the apparatus to not participate in beaconing for the duration of the scanning opportunity when entering the passive scanning mode.

19. An apparatus, comprising:

at least one processor; and

at least one memory including executable instructions, the at least one memory and the executable instructions being configured to, in cooperation with the at least one processor, cause the device to perform at least the following;

identify a scanning opportunity for an apparatus, the scanning opportunity being based upon an integer multiple of a network beacon signal interval;

if a determination is made in the apparatus to utilize the scanning opportunity, prepare a network information message and entering a passive scanning mode for the duration of the scanning opportunity; and

if a beacon message corresponding to another network is received in the apparatus while in the passive scanning mode, transmit the network information message.

20. The apparatus of claim 19, wherein a start time and duration for the scanning opportunity are defined as integer multiples of the network beacon signal interval.

21. The apparatus of claim 19, wherein if a determination is made to not utilize the scanning opportunity the apparatus is permitted to participate in beaconing within the network.

22. The apparatus of claim 21, wherein when the apparatus participates in beaconing within the network during duration of the scanning opportunity, the apparatus does not initiate transmission of data frames during duration of the scanning opportunity.

23. The apparatus of claim 19, wherein the network information message is modified by the apparatus prior to transmission to contain a network identifier corresponding to the other network, the network identifier being derived in the apparatus from the received beacon.

24. The apparatus of claim 19, wherein the network information message contains information usable by other apparatuses when synchronizing to the beacon period of the network.

25. The apparatus of claim 24, wherein the information usable by other apparatuses for synchronizing to the network further comprises diluted beacon period information.

26. The apparatus of claim 19, wherein initiating transmission comprises participating in contention for access to a wireless communication medium.

27. The apparatus of claim 19, wherein when entering the passive scanning mode the apparatus does not participate in beaconing for the duration of the scanning opportunity.